Java日期格式转换.doc

时间格式转化与计算代码（java）2007年04月13日 星期五 13:10* Title: 时间格式转化与计算*/package ;import java.util.Calendar;import java.util.Date;import java.text.*;public class DateTime public DateTime() /* * 取得系统当前时间 * return String yyyy-mm-dd */ public String getCurrentDate() Calendar rightNow = Calendar.getInstance(); int year = rightNow.get(rightNow.YEAR); int month = rightNow.get(rightNow.MONTH) + 1; int day = rightNow.get(rightNow.DATE); return year + - + month + - + day; /* * 取得系统当前时间 * return String yyyy年mm月dd日 */ public String getCurrentDate1() Calendar rightNow = Calendar.getInstance(); int year = rightNow.get(rightNow.YEAR); int month = rightNow.get(rightNow.MONTH) + 1; int day = rightNow.get(rightNow.DATE); return year + 年 + month + 月 + day + 日; /* * 取得系统当前时间 * return String yyyymmdd */ public String getCurrentDate2() Calendar rightNow = Calendar.getInstance(); int year = rightNow.get(rightNow.YEAR); int month = rightNow.get(rightNow.MONTH) + 1; int day = rightNow.get(rightNow.DATE); return year + + month + + day; /* * 取得系统当前时间 * return String yyyy-mm */ public String getCurrentDate3() Calendar rightNow = Calendar.getInstance(); int year = rightNow.get(rightNow.YEAR); int month = rightNow.get(rightNow.MONTH) + 1; /int day = rightNow.get(rightNow.DATE); return year + - + month; /* * 取得系统当前时间 * return String yyyyMMddhhmmss */ public String getCurrentDate4() Calendar c = Calendar.getInstance(); c.add(c.SECOND, 0); return + c.get(c.YEAR) + + (c.get(c.MONTH) + 1) + + c.get(c.DATE)+c.get(c.HOUR_OF_DAY)+c.get(c.MINUTE)+c.get(c.SECOND); /* * 取得系统当前时间 * return String yyyy-MM-dd hh:mm:ss */* public String getCurrentDate5() SimpleDateFormat simpleDateFormat =new SimpleDateFormat(yyyy-MM-dd hh:mm:ss); java.util.Date date = new java.util.Date(); String time = simpleDateFormat.format(date); return time; */* 取得系统当前时间* return String yyyy-MM-dd hh:mm:ss*/ public String getCurrentDate5() Calendar c = Calendar.getInstance(); c.add(c.SECOND, 0); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE)+ +c.get(c.HOUR_OF_DAY)+:+c.get(c.MINUTE)+:+c.get(c.SECOND); /* * 取得系统当前时间 常用于订单号 * return String yyyyMMddhhmmss */ public String getCurrentDate6() Calendar c = Calendar.getInstance(); c.add(c.SECOND, 0); String year=c.get(c.YEAR)+; return + year.subSequence(2,year.length()+ + (c.get(c.MONTH) + 1) + + c.get(c.DATE)+-+c.get(c.HOUR_OF_DAY)+c.get(c.MINUTE)+c.get(c.SECOND)+-+c.get(c.MILLISECOND); /* * 取得系统当前时间前n个月的相对应的一天 * param n int * return String yyyy-mm-dd */ public String getNMonthBeforeCurrentDay(int n) Calendar c = Calendar.getInstance(); c.add(c.MONTH, -n); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); /* * 取得系统当前时间后n个月的相对应的一天 * param n int * return String yyyy-mm-dd */ public String getNMonthAfterCurrentDay(int n) Calendar c = Calendar.getInstance(); c.add(c.MONTH, n); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); /* * 取得系统当前时间前n天 * param n int * return String yyyy-mm-dd */ public String getNDayBeforeCurrentDate(int n) Calendar c = Calendar.getInstance(); c.add(c.DAY_OF_MONTH, -n); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); /* * 取得系统当前时间后n天 * param n int * return String yyyy-mm-dd */ public String getNDayAfterCurrentDate(int n) Calendar c = Calendar.getInstance(); c.add(c.DAY_OF_MONTH, n); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); /- /取过去一个时间对应的系统当年的一天 public String getCurrentDateAfterPastDate(String sPastDate) if (sPastDate != null & !sPastDate.equals() Date date = switchStringToDate(sPastDate); Calendar c = Calendar.getInstance(); c.setTime(date); int iPastYear = c.get(c.YEAR); Calendar c1 = Calendar.getInstance(); int iCurrentYear = c1.get(c1.YEAR); c.add(c.YEAR, iCurrentYear - iPastYear); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); else return null; /* * 将一个日期字符串转化成日期 * param sDate String * return Date yyyy-mm-dd */ public Date switchStringToDate(String sDate) Date date = null; try SimpleDateFormat df = new SimpleDateFormat(yyyy-MM-dd); date = df.parse(sDate); catch (Exception e) System.out.println(日期转换失败: + e.getMessage(); return date; /* * 输入两个字符串型的日期，比较两者的大小 * param fromDate String * param toDate String * return boolean before为true */ public boolean compareTwoDateBigOrSmall(String fromDate, String toDate) Date dateFrom = this.switchStringToDate(fromDate); Date dateTo = this.switchStringToDate(toDate); if (dateFrom.before(dateTo) return true; else return false; /* * 将一个日期字符串转化成Calendar * param sDate String * return Calendar */ public Calendar switchStringToCalendar(String sDate) Date date = switchStringToDate(sDate); Calendar c = Calendar.getInstance(); c.setTime(date); return c; /* * 将一个日期转化成Calendar * param date Date * return Calendar */ public Calendar switchStringToCalendar(Date date) Calendar c = Calendar.getInstance(); c.setTime(date); return c; public String string2Date(String dateString) throws java.lang.Exception /*DateFormat dateFormat; dateFormat = new SimpleDateFormat(yyyy-MM-dd kk:mm:ss); dateFormat.setLenient(false); java.util.Date timeDate = dateFormat.parse(dateString);/util类型 /java.sql.Date dateTime = new java.sql.Date(timeDate.getTime();/sql类型 java.sql.Timestamp dateTime = new java.sql.Timestamp(timeDate.getTime();/Timestamp类型 */ SimpleDateFormat newk = new SimpleDateFormat (yyyy.MM.dd hh:mm:ss); SimpleDateFormat old = new SimpleDateFormat(MMM dd hh:mm:ss yyyy); String strDate = Mar 22 00:42:00 2002; Date d = old.parse(strDate); System.out.println(newk.format(d); return newk.format(d); /* * 取得某个时间前n个月的相对应的一天 * param sDate String * param n int * return String yyyy-mm-dd */ public String getNMonthBeforeOneDay(String sDate, int n) Calendar c = switchStringToCalendar(sDate); c.add(c.MONTH, -n); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); /取得某个时间后n个月的相对应的一天 public String getNMonthAfterOneDay(String sDate, int n) Calendar c = switchStringToCalendar(sDate); c.add(c.MONTH, n); return + c.get(c.YEAR) + - + (c.get(c.MONTH) + 1) + - + c.get(c.DATE); /取得某个时间前n天,格式为yyyy-mm-dd public String getNDayBeforeOneDate(String sDate, int n) Calendar c = switchStringToCalendar(sDate); c.add(c.DAY_OF_MONTH, -n); return + c.get(c.YEAR) + -